DE2810065C2 - Coiled body for containers - Google Patents

Description

The invention relates to a wound body for containers, in particular for holding beverages that contain a pressurized gas, according to the preamble of claim 1.

There is a general tendency for packaging containers for liquids to use glass through other materials to replace. With "still" drinks, i. H. those that do not contain pressurized gas will be the The gas cylinder is being replaced more and more by the lighter plastic cylinder, the advantage of which is that according to your Use to be thrown in the trash as opposed to a glass bottle that is made by the beverage manufacturer is usually withdrawn with a view to reuse after cleaning. Since the The cost of plastic is several times that of glass, the plastic bottle comes with Glass bottle has been given the thinnest possible wall thickness to compete; by means of this art

handle as well as others, for example the increase in the capacity of the plastic bottle with regard to that of the glass bottle, the plastic / beverage cost is comparable to the glass / beverage cost become.

When drinking beverages with pressurized gas, generally carbon dioxide CO ₂ , a completely different problem arises. In order to be able to withstand the gas pressure inside the bottle, which can be several kg / cm ² , it is absolutely necessary to To increase the wall thickness of the plastic bottle. However, this means that it is no longer competitive with a »· glass bottle. There are also other factors in favor of glass, such as the better impermeability of glass to CO ₂ on the inside of the bottle and to air on the outside of the bottle compared to the vast majority of plastics currently available on the market Not to mention that glass is a completely non-toxic material, which is far from being the case for plastics. These different aspects of the problem will be considered in greater detail in the following description.

Another type of packaging that uses conventional glass packaging for drinks with an under Pressurized gas is in competition, the cylindrical metal can is of the type for preservation of meat, vegetables, fruits, milk etc. already well-known cans. For example the cylindrical metal can for holding gaseous beverages generally has a capacity from about 0.25 to about 0.481. The ratio of packaging weight to beverage weight, that still is below the corresponding weight ratio for a glass bottle of the same capacity, is nevertheless considerable. Another disadvantage of the metal can is that, on the one hand, it empties and throws it into the garbage thrown takes up a considerable volume and on the other hand is practically indecomposable, which is serious creates ecological problems. Therefore, the intention is to use materials as metal substitutes for the Look for the manufacture of this type of can.

Cans of this type are already known. The conventional metal (tinned steel, aluminum, etc.) partially replaced by non-metallic materials for the manufacture of the cylindrical body of the can. So are provided according to US-PS 36 87 351 for the cylindrical body a) a thick and robust band Aluminum or steel, which forms the inner wall of the body, b) a middle layer of cardboard on both sides an adhesive coating and c) an outer, extruded layer of plastic. According to US-PS 39 80 107 are provided for the wall of the cylindrical body a) an inner lining consisting of the inside out modified from a polyester film, a polyethylene adhesive layer, an aluminum tape and a vinyl lacquer layer with polyethylene terephthalate, b) an outer covering made of a rigid material consisting of two cardboard layers separated from one another by a polyethylene layer and c) one on the outside of the Wrapping glued-on paper label These cans show the ratio of the weight of the packaging to the weight of the beverage improve, but still have a metallic band, eliminating the problem of environmental pollution is not fully resolved. It should be noted, however, that so far this has been the case with these doses metallic band used, be it completely metallic or only partially metallic, one multiple plays a significant role, namely it forms a tight barrier that the passage of gases and liquids prevented through the container wall, and gives this type of packaging the necessary properties mechanical strength.

The ideal, of course, would be to have the cylindrical body made entirely of the can a material other than metal that would be completely degradable by incineration or by aid atmospheric agents, which would completely solve the pollution problem. It would be called The only remainder are the metallic lids that form the bottom and the cover of the container which represent only a negligible proportion of the can in its entirety, both in terms of on weight as well as volume; in the present case, this cover could even be made of plastic exist; thereby completely solving the pollution problem.

The difficulty, however, is to find a material that is the same as that used so far for the cylindrical Can body used to completely replace metallic straps. This material should be the meet the following requirements:

(1) It should be completely non-toxic, i.e. H. be physiologically acceptable,

(2) it should be organoleptically neutral to the taste properties of the packaged gaseous Not to change the drink,

(3) it should be sufficiently impermeable to gases, in particular to oxygen, to carbonic acid and to Water vapor, so that the ingested drink keeps its original properties during at least one year completely preserved,

(4) it should be able to withstand the internal pressure of the gases, which can reach 10 kg / cm ² for non-pasteurized beverages in their packaging and 15 kg / cm ² for pasteurized beverages,

(5) it should be able to withstand the pasteurization temperature, which is of the order of 70 ° C,

(6) it should be creep and flow resistant so that the can does not increase its volume, which leads to a CO 2 loss would lead to an organoleptic change in the drink as a result of relaxation,

(7) It should be able to withstand impact, compression and bursting in the course of storage and of transport,

(8) It should have a thickness as small as possible, and at the same time a ratio between the packaging weight and to have the beverage weight as low as possible, the cost price of the packaging to lower and to enable heat exchange processes in the course of pasteurization,

(9) it should be printable using the usual printing techniques,

f 1 0) it should be incinerable or decomposable under the action of atmospheric agents after

use without releasing toxic fumes or gases into the environment.

The systematic review of the properties of plastics in general shows that there are none simultaneous complete fulfillment of all of the above requirements. It is therefore necessary to solve the ins Considered task of the complete replacement of metallic strips by plastics necessary several To select kinds of them so that by their simultaneous use a composite material is achieved that meets the above requirements in their entirety, provided that This selection is possible, the selected plastics must also be mutually compatible. In In a negative sense, the problem arises of making these plastics mutually compatible by means of a trick that remains to be found. In addition, the order in which these different Plastics are to be arranged one above the other in the cylindrical wall of the can, yet to be strictly defined. Furthermore, the critical thickness or strength of each of these plastics is allowed to achieve the desired properties and likewise the total thickness of the wall of the cylindrical can body thus obtained cannot be great in view of the fact that the cost of this composite material becomes unduly high. Under a

Another aspect is that this composite material must be used in conventional machines Manufacturing cylindrical body can be processed to in technical and economic terms avoid unacceptable investment costs. From the same point of view it is necessary that so reached cylindrical bodies without particular difficulties with the help of bottom and end covers usual machines provided for this purpose can be locked. After all, provided that that the two conditions given above with regard to the plants for the production of the can are met are still necessary that the can to be produced by the manufacturer of gaseous beverages on conventional Can filling systems or machines can be used. It can therefore be seen that what is being envisaged Target encounters a significant number of difficulties in its realization, which explains why that currently no bottles for holding gaseous beverages are known whose cylindrical body consists entirely of one or more plastics in the complete absence of conventional ones Materials such as metals, cardboard, textiles, etc.

A wound container body of the type indicated at the beginning is from the already mentioned US-PS 39 80 107 known. To make these "wound bodies," tapes of the individual above are also used Components of the overall multi-layered material already designated after winding individually successively wound on a mandrel. An essential material component is what is intended Aluminum tape, consequently container made from the wound body by no means all of the requirements meet, which are placed on a glass replacement body.

From GB-PS 9 97 955 a thermoplastic polymer film is known which has a on one surface Has two-layer coating. The lower coating layer consists of a copolymer

sufficient by copolymerizing up to 50% vinylidene chloride, 40-90% alkyl acrylate and 10-30% acrylonitrile, each in percent by weight. The top layer of the coating consists of a copolymer achieved by Copolymerize 80-97% vinylidene chloride and 3-20% at least one other copolymerizable therewith olefinic monomer, preferably alkyl acrylate. The other surface of the film is coated in a single layer, namely with the material of the coating top layer of the other surface. So this in total multilayer film is intended in particular for the production of bags, containers and similar packaging serve, the purpose of the coatings being to impart certain properties to the actual film improve, for example, to improve the heat sealability and at the same time the tendency to stick to Reduce heat sealing tools. At the same time, there is a certain impermeability to it Gases and water vapor reached, but it is all in all a multi-layer laminate that after Appropriate processing into containers would make them unsuitable for accommodating under beverages under internal gas pressure.

Finally, from DE-OS 16 29 360 a packaging film in the form of a multilayer film is known, with a resinous polyolefin for the outer layers on each side of a resinous inner barrier layer and a transparent adhesive layer is provided between them. The adhesive layer consists here

For example, from chlorinated polyethylene, polyvinyl chloride or a copolymer of ethylene with vinyl acetate, isobutyl acrylate or ethyl acrylate, while for the resinous polyolefin layer, for example, polyethylene and polypropylene, but also copolymers of vinylidene chloride with at least one other olefinically unsaturated and copolymerizable monomer are used. However, due to its detailed structure, this known laminate film does not show any impermeability, in particular with regard to oxygen and CO ₂ , which would make it appear suitable for producing containers for receiving beverages under internal gas pressure. However, the structure of this known multilayer film is also one in which no measures are provided as a result of which the film could withstand the pressure of a gas that prevails inside the receptacle made from it
The invention is based on the object of designing the initially described wound body for containers for holding beverages that contain a gas under pressure so that only plastics, not glass or metal, are used, but all of them Requirements specified in detail above for a container to be produced from such a wound body are met by the latter.

This object is achieved by the measures specified in the characterizing part of claim 1 solved

According to the invention in the form of the member a used synthetic or semi-synthetic polymer has an oxygen permeability less than 6 χ 10 ~ ¹³ ml · cm / cm ² - hold at 25 ° C and 0% relative humidity see · cm Hg. It is essential that the atmospheric

Oxygen does not come into contact with beverages under pressure in the container can occur, taking into account the well-known negative effect of oxygen on the Preservation and the organoleptic qualities of beverages, such as beer, lemonades, etc. The barrier properties against oxygen vary considerably from polymer to polymer. It is It is therefore necessary to make a selection among those polymers which are the most effective and which Oxygen permeability is less than the value given above because otherwise it would be necessary when Container to use such a thickness of the element a that this type of packaging is too expensive and in its Function would be unsuitable. Therefore, the polyvinyl alcohol is preferably selected for the element a and the copolymers with at least 70% by weight vinyl alcohol units, the regenerated cellulose, the Polyacrylonitrile and the polymethacrylonitrile as well as the copolymers with at least 65 wt .-% acrylonitrile or Methacrylonitrile and the copolymers of vinylidene chloride with at least 85% by weight of vinylidene chloride units, whose oxygen permeability is in the order of their size as follows:

Oxygen permeability
(ml · cm / cm ² · see · cm
Hg column at 25 ⁰ C and 0%
relative humidity)

Polyvinyl alcohol

Copolymers of vinyl alcohol regenerated cellulose polymethacrylonitrile
Copolymers of methacrylonitrile Copolymers of vinylidene chloride

approximately

approximately
approximately
approximately

6.24 χ 10- "
1.5 χ 10- ' ⁴
8.94 χ ΙΟ " ¹⁴
2.2 χ 10- ' ⁴
5 χ ΙΟ- "
2-5 χ ΙΟ- "

Examples of copolymers of vinyl alcohol are those with a maximum of 30% by weight of ethylene, vinyl acetate, Etc.

Examples of copolymers of acrylonitrile and copolymers of methacrylonitrile are those with not more than 35% by weight of styrene, methyl methacrylate, butadiene, etc.

Examples of copolymers of vinylidene chloride are those with a maximum of 15% by weight of acrylonitrile, Methyl methacrylate, itaconic acid, etc.

Among the polymers used for element a, polyvinyl alcohol is very particularly preferred, the copolymers of vinyl alcohol and regenerated cellulose, especially polyvinyl alcohol, for this particular selection not only the factor of oxygen impermeability is taken into account but other considerations such as physiological harmlessness, mechanical properties, Among other things, the resistance to tension and creeping or flowing, etc.

The polymers used for element a are commercially available in the form of films with different Thicknesses available. These films can optionally be biaxially oriented.

Taking into account the fact that the polymers, such as, for example, polyvinyl alcohol, the regenerated cellulose, the polymethacrylonitrile, sensitive to moisture and waste at the same time which are barrier properties to oxygen for increased moisture absorption Certain manufacturers equip these types of films with a thinner polymeric coating that has a Forms moisture barrier, for example with a polyvinylidene chloride coating. It goes without saying that these coated foils can obviously also be used for element a.

Depending on the particular barrier properties against oxygen for the element a Usable polymeric films can be one or more of these films for the production of the cylindrical Body to be used.

It should be noted that element a also acts as an impermeable barrier for CO2, which is released by the pressurized beverage, which in turn is held inside the container.The criterion for the oxygen permeability required by element a is namely less than 6 10 "ml · cm / cm ² · seconds - ct. Of mercury column is sufficient to simultaneously _{prevent the passage of CO 2} to the open air through the wall of the body in the opposite direction.

Element b consists of a large number of polyester films, including polyester as a polycondensation product of terephthalic acid with alkylene glycol such as ethylene glycol, butylene glycol, 1,4-cyclohexylene dimethanol, etc, whereby a smaller proportion of the terephthalic acid is further replaced by another polybasic Carboxylic acid can be replaced. A classic, but not limiting example of a polyester film is Mylar from E. I. Dupont de Nemour & Co. The polyester film is preferably made made of biaxially oriented polyethylene terephthalate, the mechanical properties of which are those of the corresponding ones are clearly superior to the non-oriented type. The role of element b in the cylindrical body is very meaningful because it also has the properties of resistance to this Internal pressure of the gases in the can, the creeping or flowing, the impacts, the upsetting and the heat and gives the strength of the cylindrical can body. In addition, the polyester is completely non-toxic and organo-optically neutral, which means that it can be used advantageously (but not necessarily) as an inner film of the cylindrical body allowed to come into direct contact with the pressurized beverage

Element c is an organic, thermoplastic adhesive or binder, the water vapor permeability of which is less than 1 χ 1O ~ ¹⁴ g · cm / cm ² - see ■ cm mercury column at 38 ° C and 90% relative humidity. Element c plays a double role Role, namely on the one hand for the adhesive union of the manufacturing

elements a and b used in the material for the cylindrical body and, on the other hand, to form a moisture-proof barrier, thus taking into account the possible water sensitivity of component a as indicated above. In addition, the element c must have a softening temperature sufficiently high that the cylindrical body of the can can withstand the action of heat, be it in the course of temporary storage or in the case of pasteurization of the beverage when it is already contained in the can. Therefore, the element has c, preferably, a softening temperature of at least 6O ⁰ C, advantageously of at least 8O ⁰ C. Furthermore, the element molten state must c in the liquid or which have sufficiently low viscosity that it without difficulty in layers of some μΐη thickness can be distributed on the elements to be glued a and b. Non-restrictive ίο examples for element c are the adhesive compositions called "hot-melt" in the Anglo-Saxon language, which have one or more of three components I), II) and III):

(I) A synthetic polymer selected from polyethylene, ethylene / vinyl acetate copolymer, ethylene / propylene / diene / terpolymer, polyisobutylene, polypropylene, polyamide, polyes ··? "·.
(II) a natural or synthetic adhesive resin with low molecular weight, such as polyterpene, phenolic terpenes, terpene urethane resins, phenolic resins, natural or modified rosin

to, copolymer resins of styrene;
(III) a water-repellent wax such as the paraffins and the microcrystalline waxes, preferably the latter,

the presence of the component HI) in the element c is mandatory.

The components I), II) and IH) are selected according to type and weight such that the above for the element c required properties are met. There are various compositions that are not to be understood as limiting for element c in the examples which illustrate the present invention.

The elements a, b and c described above are essential and indispensable for the Manufacture of the cylindrical body of the container. However, it is for certain reasons, such as because of the decrease in the cost of the container, the search for decorative effects, the momentary Dilution of one or the two elements a and b possible, remaining entirely within the scope of the invention furthermore to use at least one element d, the at least one organic, polymeric Fclie other than the films a and b is examples of the element d are different films of an organic polymer which are currently used in the packaging sector and are in no way intended to be limiting A preferably bioriented polypropylene film, made entirely or partially, can be mentioned paper made from synthetic fibers and in particular one under the Anglo-Saxon name "Spun-bonded" well-known film etc.

If the element d is simply provided in addition to the structures a, b and c for the manufacture of the cylindrical body, there are no particular problems, since the elements a, b and c alone meet the stated requirements for the cylindrical body of the container. If, on the other hand, element d partially replaces element b, it must be used in such a manner and in such a quantity that the cylindrical body has the same mechanical properties as in the case where element b is used in the absence of element d, The mechanical properties in the main order are the resistance to the internal pressure of gases of the container filled with the pressurized beverage, the resistance to creep or flow, to impact, to compression, to heat and the strength or rigidity
As indicated above, the elements a, b and c and optionally d are assembled in such a way that the cylindrical body of the container has a spiral or wound structure continuous, helically wound bands on a mandrel is known per se and is described in particular in the patent literature (US-PS 39 80 107, US-PS 36 87 351, US-PS 39 60 624, US-PS 35 24 779, GB -PS 1432 788). Each individually viewed foil strip becomes

helically wound on the mandrel, with its edges in mutual abutment or overlap stand. The various bands forming the cylindrical body are helical one above the other arranged, the bands being arranged obliquely below one another in the longitudinal direction of the dome, so the connections or connections of each tape are covered by the tape that is directly above it is arranged, whereby the tightness is thus ensured. The element c is used for gluing the tapes used among each other

In the rolled-up design or manufacture of the cylindrical body, these are the components forming film strips discontinuous strips, and these have a width of about one to several times (in the case of cutting) the height of the cylindrical body to be produced. The first tape will be on the mandrel wound on itself one or more times; then the second tape on or with the first tape wound; then the third tape is wound onto or with the second tape, etc. All of this covering the connection or the connection of each band by the following band to guarantee the tightness Now the further element c is used to glue the different tapes used Wrapped structures are addressed in US Pat. No. 3,524,779, among others. It should be noted that in the PS's given above with regard to examples of spiral or wound structures combinations of materials are used which differ from the inventive combination of elements a, differentiate between b and c.

As already indicated above, element c is preferably an adhesive combination called “hot-melt”. The application of the element c on the foils of the element a and / or b can be preferred

Way, just before the formation of the cylindrical body, carry out by spiral winding on the mandrel. This application technique for a "hot-melt" composition is detailed in the following Articles described: Wendell T. Kopp, Hot Melt Equipment, Package Priming and Diecutting, September 1974, Pages 10, 11, 92, 94, 95 and October 1974, pages 12 to 14.

In the case of the cylindrical body, the position or arrangement of the elements a, b, c and optionally d strictly determined. As indicated above, each sheet of element a is both on the outside surface and on the inner surface of the cylindrical body kept separate, with the help of at least one film of the Element b and at least one layer of element c. If or there the element c is at the same time a barrier is against moisture, every foil of the element a is therefore completely protected against moisture, which from the outside atmosphere, and against moisture also from the liquid inside the cylindrical container body of pressurized beverage.

If only elements a, b and c are used to manufacture the cylindrical body both its outer surface and its inner surface always built up by means of a film of the element b, the with the aid of element c either on one or more further inner foils of element b and / or one or more inner foils of the element a is glued on

When using the optional element d, the mandatory elements a, b and c can be used the optional element d any position on the inside of the wall of the cylindrical body or on Take the exterior of the same. However, if the optional element d is physiological and organoleptic acceptable organic polymer, so it can also form the inner surface of the cylindrical body, which is in direct contact with the beverage under pressure.

An important factor for the cylindrical body is the thickness or strength of its wall, as it is at the same time the condition for the upper limits of the thickness of the elements a, b, c and possibly d is the wall thickness must be sufficient to achieve the required durability of the container manufactured by means of the cylindrical body ensure by ensuring complete preservation of the pressurized beverage at the same time will be for a period of at least one year. On the other hand, the wall thickness must not be so great that the advantage of the low specific weight of the plastics is generally lost and the weight and cost of this type of packaging are unduly increased. Hence the wall thickness of the cylindrical body in general between 85 and 770 μm, preferably between 100 and 400 μm.

The thickness of the element a in the case of the cylindrical body depends on its degree of impermeability versus oxygen. The greater this impermeability, the smaller the thickness of the element a can be. Consequently, the element a can be formed from one or more foils, in particular depending on the commercially available thicknesses of the foils of the element a. The total thickness of the element a that consists of consists of one or more foils, is generally in the range from 10 to 250 μm. Especially with that preferred case of using polyvinyl alcohol or its copolymers is in view of the Element a, the thickness of the layer preferably between 10 and 80 μm.

The thickness of the element b in the cylindrical body is a function of that of the packaging container required mechanical properties. Element b consists of at least two each side of element a protective foils, the number of these foils of the element b also being a function of the commercially available Available thicknesses of the foil b is the total thickness of the element b, which consists of two or more Films consists is generally in the range from 35 to 250 μm, preferably 35 to 180 μm.

The thickness of the element c in the cylindrical body must be sufficient, at the same time good mutual To ensure bonding of the foils of the elements a and / or b and an effective barrier against To form moisture, both on the atmospheric side and on the side of the inside of the Can of pressurized beverage. Obviously, the number of layers of the element c is one Function of the films to be bonded of the element a and the element b, while their total thickness, conditional due to their impermeability to moisture generally in the range from 40 to 70 μm, preferably 50 to 65 μm. Cherishes

The thickness of the element d optionally used in the cylindrical body depends essentially on its mechanical properties and its barrier properties against oxygen and CO2. It is well known that the mechanical properties of polymer to polymer are considerable can fluctuate; therefore it is practically impossible to set a precise limit for the thickness of the element d specify which can be used when using such an element. The essential criterion is, however, that the thickness of the optionally used element d neither the mechanical Properties nor affect the barrier properties against oxygen and CO2 of the cylindrical body can that have been given to this by means of the element a. In general, the thickness of the Element d can be between 0 and 200 µm.

The manufacture of the container for which a cylindrical body and shooting elements at its two ends can be used in the way of conventional techniques from the field of filling or packaging of run pressurized beverages in cans. The arrangement of these elements on the cylindrical Body can thus be made in conventional automatic machines using "known methods." for gluing, thermal welding and, in particular, flanging, the latter The method is particularly preferred for receiving pressurized beverages containing gas as a result of its increased production rate.

Furthermore, the cylindrical body easily represents various conventional types of decoration for cans for holding pressurized beverages. Thus, metallized or non-metalized paints, varnishes, inks and printing features etc. on the back or front of the last and / or penultimate bands of the cylindrical hollow body are applied, which are made of a film of the Elements b and / or d exist. Furthermore, the application of labels on the outer surface of the cylindrical

see the body in the way of a customary gluing.

The advantages of the container compared to the state of the art are considerable:

- In contrast to conventional cans, which have a metallic band, there is a cylindrical one Body made entirely of plastics, which can be completely destroyed or decomposed by incineration and also in the long run under the action of atmospheric agents, what with regard to the Ecology is beneficial;

- Compared to conventional cans, the container is significantly lighter because of its entirely organic body. Thus, the weight (4-7 g) of a cylindrical body with a volume of 330 c? N ³ is much less than that of a corresponding cylindrical body made of tinplate (about 35 g), of aluminum (about 13 g) and a corresponding cylindrical body Body according to US-PS 3687 351 made of aluminum cardboard (about 11.3 g), which results in a considerable economy of the first material and a very advantageous ratio of dead weight to useful weight;

- With regard to an unexpected advantage, the container has due to the relatively small Weight of a cylindrical body over a very low center of gravity, since it is only over has a bottom lid, at least at the moment of filling with the gaseous drink; this very The low center of gravity provides exceptional stability for the container in the vertical position Filling machines safe, clearly superior to those of conventional cans, whose cylindrical body is heavier than in the context of the present invention, which leads to the achievement of at least the same FOI-lungsrate the doses allowed with the drink to be ingested;

- At present, all forms of pollution, and in particular noise, are being vigorously combated it has now been established that in the manufacture of the body and container as well as in the course of the filling the same with a pressurized drink the noise of the machines is much less intense than in the case of conventional cans, which is due to the acoustic insulation properties of the Production of the material or material used in the container according to the invention.

Show in the drawings

F i g. 1 is a perspective view of a closed can, the cylindrical body of which is produced by the technique of spiral formation (FIG. 1 A), and of a cylindrical body shown without a cover lid, which is produced by the technique of wound rolling (FIG. 1 B) is established,
F i g. 2 shows a longitudinal section along the line 2-2 in FIG. 1 A,

F i g. 3 and 4 variants of the connection connections according to FIG. 2 produced in the course of execution of the Spiral formation,

F i g. 5 shows a longitudinal section along the line 5-5 in FIG. 1 B,
F i g. 6 shows a cross section along the line 6-6 in FIG. 1 A,

F i g. 7 shows a cross section along line 7-7 of FIG. 1 bunch

F i g. 8 shows a variant of the connection terminal of FIG. 7 manufactured by means of the technology of the wound Rolling up.

In the drawings, a container is shown in the form of a can with a vertical cylindrical body which is closed by means of a horizontal cover and a bottom of the same kind ^. ! It will be understood that the essential feature in the all plastic cylindrical body is that the upper and lower closure members can be any. Thus, these closing elements can in particular consist of simple thermally encapsulated or closed connections or terminations. Furthermore, the container equipped with the cylindrical body for the upper closure element can have any device or configuration which allows the contents of the container to be dispensed in the form of a jet, aerosol, etc. In other words, using the cylindrical Body-built container beyond its special purpose for holding pressurized beverages containing gas can serve just as well for preserving or holding pressurized liquids, pastes, suspensions, etc., not only in the food sector, but also in other commercial sectors , to which in particular the pharmaceutical, phytopharmaceutical, cosmetic etc. area belong. In addition, since the containers constructed with the aid of the cylindrical body are particularly intended and suitable to withstand relatively high pressures, it goes without saying that they are all the more suitable for the packaging of products under normal pressure, in particular as containers for Food preserves, for "still" liquids, such as non-gaseous drinks, vegetable, animal or even mineral oils, non-pressurized capillary lotion, etc.
The following examples explain the invention without being restrictive.

example 1

A cylindrical body for a can as in FIG. 1 A shown by way of the known per se Technique of spiral formation produced at a spiral formation angle of about 30 °. From the representation according to F i g. 2 it can be seen that the wall of the cylindrical body has the following composition:

- Layers A, B, C, E, F and G of element b, which consists of a commercially available under the name Mylar A (du Pont) known bioriented polyethylene terephthalate film with a nominal thickness of 23 μσι consists,

- A layer D of the element a, which is made up of a bioriented and coated with a polyvinylidene chloride varnish Polyvinyl alcohol film coated on both sides with a nominal thickness of 15 μm, the

Foil is the product sold by Unitika under the trade name En.olar OV,

- Layers H of the element cdas consisting of a "hot-melt" adhesive, each layer H having a thickness of t: has about 10 μπι

The »hot-melt« adhesive used as element c has the following composition:

1) 60 parts by weight microcrystalline wax, pour point 82 ⁰ C (180-185 Be Square Company Bareco;

30 parts by weight of an ethylene / vinyl acetate copolymer (72/28) with a density of 0353 and a melt index of 1 2 (E VA-508 from Union Carbide); 10 parts by weight of alpha-methylstyrene / vinyl alcohol resin with a density of 1.04 and a pour point of jo 120 ° C (Piccotex 120 from Pennsylvania Industrial Chemical Corporation).

The following two »hot-meltw compositions can also be used for element c:

2) 40 parts by weight of polyethylene resin having a softening point (ball and ring) of 106 ⁰ C, a density of 0.908 and an acid number of 5 (Epolene C16 from Eastman Chemical Products); 40 parts by weight of hydrogenated microcrystalline wax, drop point according to ASTM D 127: 76 ° C (P. Mobilwax 2360 from Mobil);

20 parts by weight of pentaerythritol ester of hydrogenated rosin, density: 1.07; Softening point (Hercules drop method): 102-110 ° C (Pentalyn H from Hercules);

3) 40 parts by weight of amorphous polypropylene resin, density: 0.86; Softening point: 107 ⁰ C (Epolene M 5 W from Eastman Chemical Products);

50 parts by weight of microcrystalline wax, dropping point according to ASTM D 127: 87.8 ° C (Multiwax 195 M from Witco Chemical); 10 parts by weight of terpene resin based on beta-pinene, density: 0.98; Softening point: 135 ° C (Piccolyte S135 from Pennsylvania Industrial Chemical Corporation).

Example 2 According to FIG. 2, the wall of the cylindrical body has the following composition:

- Layers A, B, F and G of element b made of a bioriented polyethylene terephthalate film (Melinex S from ICI) with a nominal thickness of 23 μm,

- Layers C, D, E of the element a of a film made of regenerated cellulose, which is coated on both sides with a polyvinylidene chloride layer (film 340 XS from UCB - Sidac), with a weight of 34 g / m ² , with a thickness of about 21 μm ,

- Layers H of the element c from the "hot-melt" adhesive specified in Example 1 under 2), each layer H having a thickness of about 10 μm

Example 3
According to FIG. 2, the wall of the cylindrical body consists of the following composition:

- Layers A, B, C, E, F and G of element b made of a bio-oriented polyethylene terephthalate film (Terphane H of the Cellophane Francaise), nominal thickness 23 μm,

- a layer D of the element a of a fully saponified ethylene / vinyl acetate copolymer 25/75, flow point 180 ⁰ C; Freezing point: 74 ° C, melt index: 1.1 (Eval from Kuraray), nominal thickness of 25 μm,

- Layers H of element c from a "hot-melt" adhesive specified in Example 1 under 3), each Layer H has a thickness of about 10 μm.

Example 4
As shown in FIG. 2, the wall of the cylindrical body has the following composition:

- Layers A and G of element b made of a bioriented polyester film (Mylar A from du Pont), nominal Thickness 23 μm,

- A layer D of the element a made of a bio-oriented polyvinyl alcohol film coated on both sides with a polyvinylidene chloride layer (Emblar OV from Unitika), nominal thickness 15 μίτι,

- Layers B, C, E and F of element d made of bio-oriented polypropylene film, density 0.91 (Propafilm O from ICI), nominal thickness 25 μm,

- Layers H of element c from the "hot-melt" adhesive specified in Example 1 under 1). where each Schi, lit H has a thickness of about 10 μm.

The following is an overview of the properties of packaging cans produced using a cylindrical body with the composition given in Examples 1 to 4 above. To enable By comparison, all of these cans are 6.3 cm in diameter and 12 cm in height.

The internal pressures that the cans can absorb follow the equation below:

where S - limit of elastic elongation (in kg / cm ² ),
P = internal pressure (in kg / cm ² ),

D - diameter of the can (in cm), d - thickness of the wall (in cm)
mean.

The maximum tolerable internal pressure at 70 ° C (pasteurization temperature) for one at an angle jo of 30 ° spirally shaped body is represented by the following equation, where the by Measurement of the value of S obtained for each cylindrical body of Examples 1 to 4 is known:

For explanation, the following example is given, in which the limit of the elastic expansion of the spirally shaped body of Example 1, which has a thickness of 0.0213 cm, is 1800 kg / cm ² , which is indicative of the maximum tolerable pressure at 70 ° C (pasteurization temperature) is at:

ρ 2xdx5 _ _ ^ ^^

_ 2xdx S Limit of elastic
Elongation at 70 "C
kg / cm * Wall thickness max.pressure
in um kg / cm ² 12.17
8.19
11.23
932 COr content
of the drink
g / liter 1800
1200
1600
1400 213
215
223
221 8th
6th
7.5
6.5 '~ D
The results obtained are shown in the table below : composition example 1
Example 2
Example 3
Example 4

This pressure corresponds to that of a carbonated beverage with a CO2 content of 8 g / liter.

Example 5

This example concerns a cylindrical body, its structure (Figs. 1B, 5 and 7). This structure possesses the following composition:

- Layers A ', C, D' and E 'of element b made of bio-oriented polyester film (Mylar A from du Pont), nominal Thickness 35 μm,

- A layer B 'of the element a made of bio-oriented polyvinyl alcohol film coated on both sides with a varnish based on polyvinylidene chloride (Emblar OV from Unitika), nominal thickness 15 μm,

- Layers H 'of element c from the "hot-melt" adhesive specified in Example 1 under 1), each Layer H 'has a thickness of about 10 μm.

For a jar with a diameter of 63 cm and a height of 12 cm, the following values are achieved:

- elastic elongation limit at 70 ° C (kg / cm ² ): 1800,

- wall thickness (in μπι): 195,

- Maximum pressure (kg / cm ² ): 11.14,

- CO ₂ content of the drink (g / liter): 7.5.

Example 6

In the foregoing Examples 1 to 5, by calculation, the maximum performance is a cylindrical body for the production of a standard jar with a diameter of 6.3 cm and a height of 12 cm been.

However, the thickness to be given to the wall, depending on the potential pressure of the filled liquid can be calculated for a given can diameter.

In fact, the math equation given in Example 4 can also be written as:

. P- D

where d - thickness of the wall in cm,

P »internal pressure in kg / cm ² , D = diameter of the can in cm,

S = elastic elongation limit in kg / cm ² .

It follows from this equation that the value of the wall thickness (d) must be increased if the can diameter (D) and / or the pressure (P) prevailing inside the can is increased.

The pressure (P) inside the can is a function of the dissolved gas content of the liquid contained in the can and also the temperature to which the liquid inside the can must be subjected. For example, a beer normally contains around 5 g CO2 / liter. If the can containing this beer does not need to be subjected to pasteurization, the internal pressure (P) reaches a maximum value of about 4 kg / cm ² for a maximum storage temperature of 40 ° C. On the other hand, if the can containing this beer is to be subjected to pasteurization, it can this lead to a maximum temperature of about 70 ° C and a maximum internal pressure (P) of about 7 kg / cm ² . The wall thickness of the cylindrical can body could thus be smaller in the first case than in the second case. The following abbreviations are used in Examples 6.1 to 6.5:

Emblar OV = bio-oriented polyvinyl alcohol film (see example 1) (element a). PAN = polyacrylonitrile film / Barex 210 from Lonza) obtained from a resin with

70% by weight of an acrylonitrile / methyl acrylate copolymer (80/20) and 30% by weight of an elastomeric acrylonitrile / butadiene copolymer (40/60).

Saran = film obtained from a vinylidene chloride / vinyl chloride / acrylonitrile copolymer

sat (85/13/2) distributed by Dow (item a).

PETP = Mylar bio-oriented polyethylene terephthalate film from du Pont (element b). Hot melt = The adhesive (elements) specified in Example 1 under 1).

Tyvek 1073 = sheet of spun-bonded synthetic paper made of high-density polyethylene fibers from du Pont (element d).

Example 6.1

Conditions: 5 g of beer with QVLiter (P _m "" * ■ 4 kg / cm ²⁾ no pasteurisation can diameter 40 mm PETP having an elastic elongation limit of 1870 kg / cm ² at 40 ⁰ C.

For the PETP: d = = = about 0.0043 cm or 43 μm.

The cylindrical body is made by spiral formation by using an Emblar OV film with 15 μm (element &), PETP films with 12 μm (element b) and "hot melt" layers with 12.5 μm ( Element c) have been used. It is therefore necessary to use four layers of element b (4 χ 12 = 48μιη).

But because or when the film of the element a with 15 μm has better mechanical properties than that Element b with 12 μιτι, can be envisaged, only three layers of element b instead of four Layers to use. Note, however, that the edge-to-edge spiraling technique the outer layer does not contribute to the mechanical properties; these conditions ultimately make four PETP plies or layers with 12 μm necessary.

The wall of the cylindrical body thus has the following, seen from the inside outwards specified locations:

P. 1. PETP 12 μm 2. hot-melt 12.5 μm I. ■■■ 3. PETP 12 μm fe 4. hot-melt 12.5μΐη Ρ ' 5. Emblar OV 15 μm ! ΐ 6. hot-melt 12.5 μm 7. PETP 12 μm Γ - ..; .- 8. hot-melt 12.5 μm s' .; 9. PETP 12 μm

thus thus over nine layers with a wall thickness of the cylindrical body of 113 μπι.

Example 6.2

Conditions: Beer with 5 g CO ₂ / liter (P _max = 4 kg / cm ² ) no pasteurization cans. Diameter 40 mm PETP with an elastic strain limit of 1870 kg / cm ² at 40 ° C.

60 65

1. PETP 12 μm 2. hot-melt 17.5 μΐη 3. PETP 12 μm 4th hot-melt 17.5 μίτι 5. Emblar OV 15μΐη 6th hot-melt 35 μπι 7th PETP 12 μm

The difference to example 6.1 is that the cylindrical body is made by winding is. As in Example 6.1, four layers of element b are required (4 χ 12 = 48 μπι). if or because the film of element a with 15 μm has better mechanical properties than element b with 12 μπι, a layer of the element a can be considered as the equivalent of a layer of the Elements b. Further, since the cylindrical body made by winding is contrary to a cylindrical body, which is manufactured by way of the spiral formation, all PETP layers on the mechanical Participating properties or contributing to them are therefore only three PETP layers required instead of four layers. The element a is opposite to the exterior and the interior of the cylindrical body isolated by 35 μπι of the element c in one and in two layers.

The wall of the cylindrical body thus consists of the following seen from the inside out Layers:

with seven layers giving the cylindrical wall a thickness of 121 μm.

Example 63

Conditions: Beer with 5 g CCV liters (P _max = 4 kg / cm ² )
no pasteurization
Can diameter 100 mm
PETP with an elastic yield point of 1870 kg / cm ² at 40 ° C.

For the PETP: d = = = about 0.0107 cm or 107 μπι,

& J ZX lo / U

which corresponds to three PETP films with 36 μm
The cylindrical can body is made by winding or rolling. So that the layer (a) made of PAN represents a barrier with 100% effectiveness against O2 and CO2, it must be given a thickness of 250 μm. The mechanical properties of a layer of the element a with 250 μm are significantly better than those of a PETP film of the element b with 36 μm. Only two layers of element b are used instead of three layers μπι insulated Under these conditions, the cylindrical can wall, viewed from the inside out, consists of the following layers:

wherein the five layers of the cylindrical wall give a thickness of 382 μm.

Example 6.4

Conditions: Beer with 5 g CO ₂ / liter (P _max = 7 kg / cm ² )

pasteurization
Can diameter 100 mm

PETP with an elastic yield point of 1800 kg / cm ² at 70 ^° C.

For the PETP: d = ⁼ ° ' ^{0194 cm 0} ^ ¹ " ¹⁹⁴ *""·

The cylindrical body is made by means of curling using a Emblar OV film with 15 μm as element a and PETP film with 36 μm as element b. Because the slide a better possesses mechanical properties than the film b, can thus from the 194 μίτ. of the PETP the 15 μπι the Foil a can be peeled off; a substitute thickness for the film b of 194-15 = 179 μm can thus be provided which corresponds to 179/36 = 5 foils b Inside the cylindrical body protected by a total thickness of 30 μm of the element c, divided in two and three layers. Thus, the cylindrical can wall consists of seen from the inside out following layers:

1. PETP 36 μm 2. hot-melt 30 μm 3. PAN 250 μm 4th hot-melt 30 μm 5. PETP 36 μm

1. PETP 36 μm 2. hot-melt 10 μm 3. PETP 36 μm 4. hot-melt 10 μm 5. PETP 36 μm 6. hot-melt 10 μm 7. EmblarOV 15 μm 8. hot-melt 15 μm 9. PETP 36 μm 10. hot-melt 15μηι 11. PETP 36 μm

with eleven layers of the cylindrical wall giving a thickness of 255 μm.

Example 6.5 is

Conditions: lemonade with 6 g CO ₂ / liter (P _max = 5 kg / cm ² )
no pasteurization
Can diameter 65 mm
PETP with an elastic yield point of 1870 kg / cm ² at 40 ° C.

For the PETP: d = ^{= 0> 0087 cm or 87 μΐη}

The cylindrical body is rolled up using two saran sheets produced as element a each with a thickness of 51 μπι. The foils of the element a are opposite the Outer and the inside of the cylindrical body by a total thickness of the element c of 25 μπι in one or two layers separated; In addition, the two foils of the element a from each other by means of a Layer of element c separated with 10 μm

PETP films with 19 μm are used as element b. This usually makes 87/19 = 5 slides des Elements b required.

Since a saran film (element a) with 51 μπι essentially the same mechanical properties as a PETP film with 19 μm, the two Saran films can replace two PETP films. So it is theoretical only necessary to use 5-2 = 3 PETP foils for the manufacture of the cylindrical body.

Since, however, a Tyvek 1073 film with a thickness of 200 μπι (element d) is used and the mechanical properties of this film are better than those of a PETP film with 19 μπι, one more of the three PETP films given above can be replaced. So there will only be two PETP foils are used. The wall of the cylindrical body therefore faces from the inside out seen over the following layers:

40

1. PETP 19 μm

2. hot-melt 25 μm

3. Saran 51 μm

4. hot-melt 10 μm

5. Saran 51 μm

6. hot-melt 123 μm

7. PETP 19 μm

8. hot-melt 123 μm

9. Tyvek 1073 200 µm

50

the nine layers of the cylindrical wall giving a thickness of 400 μm.

For this purpose 4 sheets of drawings

55 60 65

Claims (14)

.... · ■ "Claims: ■ 1. Wrapped body for containers, especially for holding beverages that are under pressure contain stagnant gas, i.a. with a gas barrier layer, an inner polyester layer and a layer an organic, thermoplastic binder between the gas barrier layer and the polyester layer, characterized in that the gas barrier layer (element a) consists of at least one film made of a synthetic or semi-synthetic organic polymer with an oxygen permeability of less than 6 χ 10- ' ³ ml - an / cm ² · see · cm of mercury at 25 "C and 0% relative humidity, the binder layer (element c) has a water vapor permeability less than 1 ^10-14 g · cm / cm ² · s · cm of mercury at 38 ° C and 90% relative humidity and that a polyester layer applied in the same way is also present on the outer side of the gas barrier layer (element a), the both polyester layers (common element b) each consist of at least one film. 2. Coiled body according to claim 1, characterized in that the at least one film of the Gas barrier layer (element a) one made of polyvinyl alcohol, made of a copolymer of vinyl alcohol with at least 70% by weight of vinyl alcohol units, from regenerated cellulose, from polyacrylonitrile, from polymethacrylonitrile or from copolymers with at least 65% by weight acrylonitrile or methacrylonitrile or from Copolymers of vinylidene chloride with at least 85 wt .-% vinylidene chloride units 3. Coiled body according to claim 2, characterized in that the total thickness of the gas barrier layer (element a) is between 10 and 250 μπι 4. A wound body according to one of claims 1 to 3, characterized in that the one made of polyvinyl alcohol or its copolymers containing at least 70 wt .-% of vinyl alcohol units is at least one film of the gas barrier layer (Element a) and that the total thickness of the gas barrier layer ( Element a) is between 10 and 80 μπι 5. A wound body according to any one of claims 1 to 4, characterized in that the polyester each of the two polyester layers (jointly element b) is a polycondensation product of terephthalic acid with alkylene glycol selected from ethylene glycol, butylene glycol, 1,4-cyclohexylene dimethanol 6. Coiled body according to one of claims 1 to 5, characterized in that the total thickness of the two polyester layers (jointly element b) between 35 and 250 μm, preferably between 35 and 180 μπι, is. 7. Coiled body according to one of claims 1 to 6, characterized in that the organic, thermoplastic binder is a so-called "hot-melt" adhesive 8. Coiled body according to one of claims 1 to 7, characterized in that the organic, thermoplastic binder! a water-repellent wax and optionally a synthetic polymer sat and / or a natural or synthetic adhesive resin with low molecular weight. 9. Coiled body according to claim 8, characterized in that the water-repellent wax is selected from the paraffins and the microcrystalline waxes that the synthetic polymer is selected from polyethylene, ethylene / vinyl acetate copolymer, ethylene / propylene / diene terpolymer, Polyisobutylene, polypropylene, polyamide and polyester, and that the natural or synthetic adhesive Resin is selected from the. Polyterpenes, phenolic terpenes, terpene urethane resins, phenolic resins, the natural or modified rosin, the styrene copolymer resins. 10. Coiled body according to one of claims 1 to 9, characterized in that the softening temperature of the organic, thermoplastic binder is at least 60 ⁰ C, preferably at least 8O ⁰ C 11. Coiled body according to one of claims 1 to 10, characterized in that the total thickness of the two binder layers (together element c) between 40 and 70 μm, preferably between 50 and 65 μπι is. 12. Coiled body according to one of claims 1 to 11, characterized by a further layer (Element d) consisting of at least one film of preferably oriented polypropylene, of one Paper made entirely or in part of synthetic fibers or of a film, Anglo-Saxon referred to as "spun-bonded", with the total thickness of the further layer (element d) between 0 and 200 μπι lies. 13. Coiled body according to claim 12, characterized in that the further layer (element d) replaced part of the polyester layers. 14. Coiled body according to one of claims 1 to 13, characterized in that the wall thickness of the wound body between 85 and 770 μm, preferably between 100 and 400 μm